In conventional warheads there is need for an extremely fast operating explosively operated switch to perform in the arming system of the warhead. These switches need only operate once from a normally open position to a closed position but must do so in 10 microseconds or less with almost absolute reliability even though being subjected to high G-forces just before, and perhaps during, operation as well as adverse environmental conditions prior to firing. Heretofore, it has been difficult to find a switch that could operate in less than 10 microseconds, be capable of withstanding the rigorous environment of a warhead switch and still be relatively easy to manufacture, economical to produce and extremely reliable.